Ventricular fibrillation is characterized by rapid electrical impulses to the ventricles, incomplete ventricular contractions, and resultant loss of pulse and blood pressure. Defibrillating the patient depends upon identifying the situation by emergency rescuers who typically work under chaotic conditions and time pressures. Thus, delaying defibrillating may be harmful to the patient and result in long-term complications and or death.
The American Heart Association protocol for cardiopulmonary resuscitation (CPR) requires a healthcare professional to assess the patient""s pulse for five to ten seconds. Lack of a pulse is an indication for the commencement of external chest compressions. Assessing the pulse, while seemingly simple on a conscious adult, is the most often failed component of a basic life support assessment sequence, which may be attributed to a variety of reasons, such as lack of experience, poor landmarks, or a bias to either finding or not finding a pulse. Failure to accurately detect the presence or absence of the pulse will lead to adverse treatment of the patient either when providing or not providing CPR or defibrillation therapy to the patient.
Electrocardiogram (ECG) signals are normally used to determine whether or not a defibrillating shock should be applied. However, certain rhythms that a rescuer is likely to encounter cannot be determined solely by the ECG signal, e.g. non-perfusing ventricular tachycardia or pulseless electrical activity; diagnoses of these rhythms require supporting evidence of a lack of perfusion despite the myocardial electrical activity as indicated by the ECG signal.
Currently, clinicians use standalone Doppler systems to detect the patient""s pulse and to measure blood flow. Once the information is gathered by the Doppler system and processed, the rescuer then needs to gather the ECG signals and make a determination whether to defibrillate the patient. Furthermore, while the rescuer is performing CPR, the rescuer has no means of assessing the adequacy of perfusion, that is, whether the amount of blood flow is adequate. Because the pulse check or blood flow measurement is performed manually, it is subject to human error, and in an emergency situation where time is of the essence, the amount of time to gather the information before beginning the ECG signal analysis to determine whether to defibrillate the patient or continue CPR is too long thereby causing detrimental results. Also, this procedure is costly because of the need to purchase and maintain a separate piece of equipment.
Furthermore, although Doppler systems have been implemented to detect an infant""s heartbeat, these Doppler systems have not been optimized for detecting perfusion and obtaining the patient""s pulse to determine whether to defibrillate the patient. Thus, it is necessary to develop an integrated system that is quickly and easily able to determine the patient""s pulse, measure the amount of blood flow, and determine the ECG signals to make an accurate and adequate determination whether to defibrillate the patient.
In an exemplary embodiment, the present invention provides for a noninvasive cardiac resuscitation system including a cardiac resuscitation pad set integrating defibrillation-monitoring pads, which determines whether the patient""s heart is undergoing a shockable rhythm, and a Doppler pad. The Doppler pad is adhesively secured to a patient""s skin to sense the carotid pulse in the carotid artery which has been found as a key indicator of sufficient cerebral perfusion. The Doppler pad is adhesively secured to the patient in proximity to the carotid artery maintaining stability over the carotid artery and adequately isolating the system from noise caused transducer movement. Further, the Doppler pad integrates a transducer including one of multiple transmitters and receivers, a single transmitter and multiple receivers, and multiple transmitters and a single receiver covering a large area of the patient""s neck overlaying the carotid artery. Thus, the cardiac resuscitation system including the cardiac resuscitation pad set, in accordance with the present invention, provides an emergency rescuer with a high degree of certainty in obtaining a pulse reading, measuring the velocity of blood flowing through a vessel, and whether it is appropriate to defibrillate the patient.
In an exemplary embodiment, the present invention provides a cardiac resuscitation apparatus including an adhesive Doppler pad detecting a pulse signal; and defibrillation-monitoring pads, connected to the Doppler pad, detecting an ECG signal, wherein the pulse signal and the ECG signal are integrated to determine whether or not shock therapy is advised for a patient. The present invention also provides for a cardiac resuscitation apparatus including an adhesive Doppler pad including one of multiple transmitters and receivers, a single transmitter and multiple receivers, and multiple transmitters and a single receiver integrated therein detecting a pulse signal of a patient; defibrillation-monitoring pads detecting an ECG signal of the patient, wherein the adhesive Doppler pad and the defibrillation-monitoring pads are connected to the cardiac resuscitation apparatus via a single conductive cable; and a processor integrating the pulse signal and the ECG signal and determining therefrom if a pulse of the patient is present, measuring blood flow, and whether a shockable rhythm is present.
The present invention is also achieved by providing a method in a cardiac resuscitation system that includes detecting a pulse signal of a patient; detecting an ECG signal of the patient; integrating the pulse signal and the ECG signal; and determining from the integrated signals whether or not shock therapy is advised to a patient. A method in a cardiac resuscitation system includes connecting an adhesive Doppler pad and defibrillation-monitoring pads to an Automatic External Defibrillators (AEDs) or a Semi-Automatic External Defibrillators (SAEDs) via a single conductive cable; detecting a pulse signal of a patient via the adhesive Doppler pad including one of multiple transmitters and receivers, a single transmitter and multiple receivers, and multiple transmitters and a single receiver integrated therein; detecting an ECG signal of the patient via the defibrillation-monitoring pads; and integrating the pulse signal and the ECG signal and determining therefrom if a pulse is present, measuring blood flow, and determining whether a shockable rhythm is present.
The present invention is also achieved by providing a computer readable storage controlling a computer in a cardiac resuscitation system and including a process of positioning an adhesive Doppler pad relative to a carotid artery of a patient to monitor a pulse signal; positioning defibrillation-monitoring pads on the patient to monitor a shockable rhythm analysis result; integrating the pulse signal and the shockable rhythm; determining shock therapy is not advised for a patient when the integrated signal indicates that a pulse is detected or a shockable rhythm is not detected; and determining that shock therapy is advised for the patient when the integrated signal indicates that the pulse is not detected and the shockable rhythm is detected.